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Number of extreme n-breakable vectors.
2

%I #17 Mar 30 2012 17:27:01

%S 1,2,3,6,8,16,22,37,53,92,110,201,260,376,519,831,963,1592,1837,2692,

%T 3593,5298,5693,8921,11044,14664,17689,26479,27298,43387

%N Number of extreme n-breakable vectors.

%C An n-breakable vector is a vector v=(v(1),v(2),...,v(n-2)) such that each v(i) is a nonnegative integer and SUM i*v(i) == 1 (mod n-1).

%C Extreme n-breakable vectors form the set of n-breakable vectors such that every n-breakable vector component-wise dominates some vector from this set, but no two distinct vectors from this set dominate one another.

%C Number of vectors from the Hilbert basis in A141347 with the first coordinate equal 1.

%H Max A. Alekseyev and Pavel A. Pevzner, <a href="http://dx.doi.org/10.1016/j.tcs.2008.01.013">"Multi-Break Rearrangements and Chromosomal Evolution"</a>. Theoretical Computer Science 395(2-3) (2008), pp. 193-202.

%e The set of extreme 6-breakable vectors is { (1,0,0,0), (0,0,2,0), (0,1,0,1), (0,0,1,2), (0,3,0,0), (0,0,0,4) }.

%Y Cf. A141347, A141349.

%K nonn,more

%O 3,2

%A _Max Alekseyev_, Jun 27 2008

%E a(21)-a(32) from _Max Alekseyev_, Sep 16 2011